hb-ot-shape-complex-arabic.cc revision b9ddbd55930228422e82b34a141ad1b6093f5376
1/* 2 * Copyright © 2010 Google, Inc. 3 * 4 * This is part of HarfBuzz, a text shaping library. 5 * 6 * Permission is hereby granted, without written agreement and without 7 * license or royalty fees, to use, copy, modify, and distribute this 8 * software and its documentation for any purpose, provided that the 9 * above copyright notice and the following two paragraphs appear in 10 * all copies of this software. 11 * 12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16 * DAMAGE. 17 * 18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23 * 24 * Google Author(s): Behdad Esfahbod 25 */ 26 27#include "hb-ot-shape-complex-private.hh" 28 29HB_BEGIN_DECLS 30 31 32/* buffer var allocations */ 33#define arabic_shaping_action() var2.u32 /* arabic shaping action */ 34 35 36/* 37 * Bits used in the joining tables 38 */ 39enum { 40 JOINING_TYPE_U = 0, 41 JOINING_TYPE_R = 1, 42 JOINING_TYPE_D = 2, 43 JOINING_TYPE_C = JOINING_TYPE_D, 44 JOINING_GROUP_ALAPH = 3, 45 JOINING_GROUP_DALATH_RISH = 4, 46 NUM_STATE_MACHINE_COLS = 5, 47 48 /* We deliberately don't have a JOINING_TYPE_L since that's unused in Unicode. */ 49 50 JOINING_TYPE_T = 6, 51 JOINING_TYPE_X = 7 /* means: use general-category to choose between U or T. */ 52}; 53 54/* 55 * Joining types: 56 */ 57 58#include "hb-ot-shape-complex-arabic-table.hh" 59 60static unsigned int get_joining_type (hb_codepoint_t u, hb_unicode_general_category_t gen_cat) 61{ 62 /* TODO Macroize the magic bit operations */ 63 64 if (likely (JOINING_TABLE_FIRST <= u && u <= JOINING_TABLE_LAST)) { 65 unsigned int j_type = joining_table[u - JOINING_TABLE_FIRST]; 66 if (likely (j_type != JOINING_TYPE_X)) 67 return j_type; 68 } 69 70 /* Mongolian joining data is not in ArabicJoining.txt yet */ 71 if (unlikely (0x1800 <= u && u <= 0x18AF)) 72 { 73 /* All letters, SIBE SYLLABLE BOUNDARY MARKER, and NIRUGU are D */ 74 if (gen_cat == HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER || u == 0x1807 || u == 0x180A) 75 return JOINING_TYPE_D; 76 } 77 78 if (unlikely ((u & ~(0x200C^0x200D)) == 0x200C)) { 79 return u == 0x200C ? JOINING_TYPE_U : JOINING_TYPE_C; 80 } 81 82 return ((1<<gen_cat) & ((1<<HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK)|(1<<HB_UNICODE_GENERAL_CATEGORY_FORMAT))) ? 83 JOINING_TYPE_T : JOINING_TYPE_U; 84} 85 86 87 88static const hb_tag_t arabic_syriac_features[] = 89{ 90 HB_TAG('i','n','i','t'), 91 HB_TAG('m','e','d','i'), 92 HB_TAG('f','i','n','a'), 93 HB_TAG('i','s','o','l'), 94 /* Syriac */ 95 HB_TAG('m','e','d','2'), 96 HB_TAG('f','i','n','2'), 97 HB_TAG('f','i','n','3'), 98 HB_TAG_NONE 99}; 100 101 102/* Same order as the feature array */ 103enum { 104 INIT, 105 MEDI, 106 FINA, 107 ISOL, 108 109 /* Syriac */ 110 MED2, 111 FIN2, 112 FIN3, 113 114 NONE, 115 116 COMMON_NUM_FEATURES = 4, 117 SYRIAC_NUM_FEATURES = 7, 118 TOTAL_NUM_FEATURES = NONE 119}; 120 121static const struct arabic_state_table_entry { 122 uint8_t prev_action; 123 uint8_t curr_action; 124 uint8_t next_state; 125 uint8_t padding; 126} arabic_state_table[][NUM_STATE_MACHINE_COLS] = 127{ 128 /* jt_U, jt_R, jt_D, jg_ALAPH, jg_DALATH_RISH */ 129 130 /* State 0: prev was U, not willing to join. */ 131 { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,ISOL,1}, {NONE,ISOL,6}, }, 132 133 /* State 1: prev was R or ISOL/ALAPH, not willing to join. */ 134 { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN2,5}, {NONE,ISOL,6}, }, 135 136 /* State 2: prev was D/ISOL, willing to join. */ 137 { {NONE,NONE,0}, {INIT,FINA,1}, {INIT,FINA,3}, {INIT,FINA,4}, {INIT,FINA,6}, }, 138 139 /* State 3: prev was D/FINA, willing to join. */ 140 { {NONE,NONE,0}, {MEDI,FINA,1}, {MEDI,FINA,3}, {MEDI,FINA,4}, {MEDI,FINA,6}, }, 141 142 /* State 4: prev was FINA ALAPH, not willing to join. */ 143 { {NONE,NONE,0}, {MED2,ISOL,1}, {MED2,ISOL,2}, {MED2,FIN2,5}, {MED2,ISOL,6}, }, 144 145 /* State 5: prev was FIN2/FIN3 ALAPH, not willing to join. */ 146 { {NONE,NONE,0}, {ISOL,ISOL,1}, {ISOL,ISOL,2}, {ISOL,FIN2,5}, {ISOL,ISOL,6}, }, 147 148 /* State 6: prev was DALATH/RISH, not willing to join. */ 149 { {NONE,NONE,0}, {NONE,ISOL,1}, {NONE,ISOL,2}, {NONE,FIN3,5}, {NONE,ISOL,6}, } 150}; 151 152 153 154void 155_hb_ot_shape_complex_collect_features_arabic (hb_ot_shape_planner_t *planner, const hb_segment_properties_t *props) 156{ 157 /* ArabicOT spec enables 'cswh' for Arabic where as for basic shaper it's disabled by default. */ 158 planner->map.add_bool_feature (HB_TAG('c','s','w','h')); 159 160 unsigned int num_features = props->script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; 161 for (unsigned int i = 0; i < num_features; i++) 162 planner->map.add_bool_feature (arabic_syriac_features[i], false); 163} 164 165void 166_hb_ot_shape_complex_setup_masks_arabic (hb_ot_shape_context_t *c) 167{ 168 unsigned int count = c->buffer->len; 169 unsigned int prev = 0, state = 0; 170 171 for (unsigned int i = 0; i < count; i++) 172 { 173 unsigned int this_type = get_joining_type (c->buffer->info[i].codepoint, (hb_unicode_general_category_t) c->buffer->info[i].general_category()); 174 175 if (unlikely (this_type == JOINING_TYPE_T)) { 176 c->buffer->info[i].arabic_shaping_action() = NONE; 177 continue; 178 } 179 180 const arabic_state_table_entry *entry = &arabic_state_table[state][this_type]; 181 182 if (entry->prev_action != NONE) 183 c->buffer->info[prev].arabic_shaping_action() = entry->prev_action; 184 185 c->buffer->info[i].arabic_shaping_action() = entry->curr_action; 186 187 prev = i; 188 state = entry->next_state; 189 } 190 191 hb_mask_t mask_array[TOTAL_NUM_FEATURES + 1] = {0}; 192 unsigned int num_masks = c->buffer->props.script == HB_SCRIPT_SYRIAC ? SYRIAC_NUM_FEATURES : COMMON_NUM_FEATURES; 193 for (unsigned int i = 0; i < num_masks; i++) 194 mask_array[i] = c->plan->map.get_1_mask (arabic_syriac_features[i]); 195 196 for (unsigned int i = 0; i < count; i++) 197 c->buffer->info[i].mask |= mask_array[c->buffer->info[i].arabic_shaping_action()]; 198} 199 200 201HB_END_DECLS 202